How to make your own seedplate with tools you can find in any better workshop:

Essential material: -1mm stainless steel sheet -Sheet metal scissors (large table scissors that won't twist the sheet metal are best). You can also use an angle grinder with a cutting wheel. -Stamps with numbers and letters -A hammer and a piece of straight steel -Drawing needle and ruler

For a better result, I printed the tabs on a 3D printer for the tracing and for the correct alignment of the numbers when stamping to save myself time, work and get a better result, but if you don't have a 3D printer, you can do without one.

I cut the sheet metal into rectangles 90mm high and 100mm wide. I drew lines 7.5mm high, which I can then comfortably stamp numbers and letters 5mm high.

When stamping, it is essential to have a hard flat base under the sheet to prevent the sheet from warping. I used steel. If the sheet metal gets twisted while you are working, it can be straightened by laying it on the flat pad bulging upwards and tapping the unevenness with a hammer, but it is better to prevent this so that you don't unnecessarily knock the surface of the sheet metal. Any unevenness of the pad or hammer will imprint into the sheet metal.

A seedplate made in this way will survive almost anything. Enjoy your work. Not your keys, not your coins ;o)